Selection of the promising fig (Ficus carica L.) accessions using fruit‐related characters

Abstract Nowadays, fig (Ficus carica L.) fruits are consumed either fresh or dried and used for jam or spirit beverage production. Morphological and pomological diversity of 49 wild edible fig accessions sampled was evaluated. Analysis of variance revealed significant differences among the wild accessions studied using the morphological data recorded. Ripening time ranged from late July to mid‐August. Fruit skin ground color showed high variability, including cream–purple (4 accessions), purple–yellow (8), light purple (7), purple (15), dark purple (5), purple–cream (3), and cream (7). The range of fruit‐related traits was as follows: fruit length: 12.65–22.60 mm, fruit width: 10.67–24.18 mm, fruit fresh weight: 2.52–6.13 g, and fruit flesh thickness: 0.85–1.89 mm. Principal component analysis (PCA) showed 10 independent components that could explain 84.11% of total variance. Ward dendrogram created according to the data obtained revealed the variation among the accessions and showed two major clusters. The present results showed that the studied accessions had remarkable phenotypic variation, and among them, some accessions with high‐quality fruits in size, color, and taste can be planted and then used in the breeding programs. Information on the current levels of genetic diversity of germplasm is essential for devising strategies for wild forms conservation.


| INTRODUC TI ON
reported that figs could be the first domesticated tree of the Neolithic Revolution, which occurred a thousand years before cereals. It is reported that the fig plant was domesticated 5000 years before millet or wheat. Given this historical background, the evaluation and discovery of the genetic diversity of figs has been considered by scientists (Hirst, 1996).  (Condit, 1955). it is well adapted to dry weather with hot summers, which has led to the development of large roots in this plant to be able to absorb water from the soil and from distances away from the trunk. Such thermophilic trees are suitable for adaptation to consequences of the climate change and global warming, and thus allow fig trees to be grown in hot and dry areas where other species are not viable (Sugiura et al., 2007).
Today, figs are consumed both fresh and dried, and are used to produce jams or spirits. The fig tree is the oldest fruit tree known as gynodioecious and is pollinated by the bee Blastophaga psenes L. (Kislev et al., 2006). Figs have ecotypes known as common figs (unisexual ion female trees) and caprifigs (bisexual with functional male trees) and have similar frequencies in wild populations (Valdeyron & Lloyd, 1979).
Food production and security is highly dependent on the responsible use and protection of agrodiversity and gene pool. On-farm conservation has been encouraged among international initiatives to preserve the genetic diversity of local and traditional varieties (Esquinas-Alcazar, 2005 (Flaishman et al., 2008;Giraldo et al., 2005).
Iran has rich resources of different plant species. Investigating the genetic diversity of wild accessions and identifying native varieties in each region is the first step to conserving genetic resources.
Genetic erosion is one of the most serious threats to germplasm extinction. Therefore, there is little knowledge about ancient landraces (Mars et al., 2008). To protect the genetic resources of figs, several alternative conservation strategies have been considered. Morphopomological characterizations are the main basis for selection and identification of genotypes as well as evaluation of genetic diversity in figs (Oukabli et al., 2002). Morphological characterizations, including leaf-and fruit-related traits are used to better distinguish between wild and cultivated plants (Asanidzea et al., 2011). In the present study, the morpho-pomological traits were investigated to select superior wild accessions of fig crop.

| Plant material
Morphological and pomological diversity of 49 wild edible fig (F. carica) accessions sampled from natural habitats of Jasb region in Isfahan province, Iran was evaluated in summer of 2021. Jasb region is located at 34°02′54″N latitude, 50°45′28″E longitude, and 1785 m height above sea level. The appropriate distances were considered between the accessions to avoid the possibility of sampling and collecting clones of the selected trees.

| The characters evaluated
A total of 55 quantitative and qualitative morphological and pomological traits (Table 1)

| Statistical analysis
Analysis of variance (ANOVA) was performed to evaluate the variation among accessions based on the traits measured using SAS software (SAS Institute, 1990). Simple correlations between traits were determined using Spearman correlation coefficients (SPSS Inc., Norusis, 1998). Principal component analysis (PCA) was used to investigate the relationship between the accessions and determine the main traits effective in accession segregation using SPSS software. Hierarchical cluster analysis (HCA) was performed using Ward's method and Euclidean coefficient using PAST software (Hammer et al., 2001). The first and second principal components (PC1/PC2) were used to create a scatter plot with PAST software.

TA B L E 2 (Continued)
The PCA showed 10 independent components that could explain 84.11% of total variance (Table 3)  accessions. The present results showed that the studied accessions had remarkable phenotypic variation, and among them, some accessions with high-quality fruits in size, color, and taste can be planted and then used in the breeding programs.

ACK N OWLED G EM ENT
None.

CO N FLI C T O F I NTE R E S T
The authors declare no conflict of interest.

R E S E A RCH I N VO LV I N G H U M A N PA RTI CI PA NTS A N D/ O R A N I M A L S
None.

I N FO R M ED CO N S ENT
None.

DATA AVA I L A B I L I T Y S TAT E M E N T
The data that support the findings of this study are available from the corresponding author upon reasonable request.